The present disclosure relates to electronic apparatuses having solid-state image capture devices. In particular, the present disclosure relates to an electronic apparatus having a solid-state image capture device with a global shutter function. In addition, the present disclosure relates to a driving method for the electronic apparatus.
Typically, CMOS (complementary metal-oxide semiconductor) solid-state image capture devices employ a system for sequentially reading out signal charges, generated and accumulated by light-receiving sections in pixels arranged in a two-dimensional matrix, row by row. In this case, the timings of the exposures at the light-receiving sections of the pixels are determined by the start and end of reading out the signal charges. Thus, the timings of the exposures at the pixels are different from each other. Hence, when such a CMOS solid-state image capture device is used to capture an image of a fast-moving subject, there is a problem in that a captured image of the subject is distorted.
In order to overcome such a problem, a simultaneous image-capture function (a global shutter function) that realizes simultaneity of accumulation of the signal charges has been proposed in recent years and the number of applications of CMOS solid-state image capture devices having the global shutter function is also increasing.
In order to ensure that the signal charges generated by the light-receiving sections are stored until the signal charges are read out, the CMOS solid-state image capture devices having the global shutter function typically have light-blocking charge accumulation sections. In typical CMOS solid-state image capture devices, the charge accumulation sections are often configured using floating diffusion sections originally included in the pixels. Japanese Unexamined Patent Application Publication No. 2009-268083 discloses a configuration using two elements, i.e., a CCD (charge coupled device) type charge-holding capacitor section and a floating diffusion section, as a charge accumulation section to increase the number of saturation electrons.
In typical CMOS solid-state image capture devices, a pixel-sharing system in which multiple pixels share a pixel circuit is available in order to achieve higher densities of the pixels. In the solid-state image capture devices having the global shutter function, when the pixel sharing system is used for a configuration in which the floating diffusion sections are used as charge-holding capacitor sections, signals of the pixels are mixed in the floating diffusion sections. Consequently, it is difficult to employ the pixel sharing system, and thus there is a problem in a reduction in the sizes of the pixels.
In the solid-state image-capture device disclosed in Japanese Unexamined Patent Application Publication No. 2009-268083, since the signal charges are also accumulated in the CCD-type charge-holding capacitor sections and the floating diffusion sections, it is difficult to employ the pixel sharing system.